ISOTOPES TEST TYRE WEAR T ESTING tyres can be a lengthy
Page 28

If you've noticed an error in this article please click here to report it so we can fix it.
and costly business, but a new concept under development in the Akron, Ohio, laboratories of the Goodyear company is designed to alter this. Wear patterns on tyres are being discerned on runs of as little as 50 miles by means of radioactive isotopes.
Various isotopes were tried before the company settled on radioactive sulphur (S-35) and iodine (1-125), which are both relatively short-lived. In the iodine test, small circles of paper are soaked in the isotope solution and pressed on to the tyre tread in several positions. The iodine is absorbed by the rubber and the radioactivity is measured before and after the test run.
The method using sulphur is not so simple, as the isotope has to be mixed in tread rubber and laid in paper-thin strips over the tread of an unvulcanized tyre. The radioactivity of these strips is then measured before and after the test run.